The technology described herein relates generally restoration of grooves used in conjunction with seal wire, particularly to methods of restoring the profile of such grooves, and more particularly, to thermal spray techniques for such restorations.
Many gas turbine engine assemblies include a seal between adjacent surfaces of moving and non-moving parts, such as a rotating disk and a stationary structure, or between parts which have clearances between their mating surfaces. One common construction for such seals utilizes a seal wire formed of one or more segments which is inserted into a groove in one part and biased against the opposing part in sealing engagement.
During operation, the constant contact between the seal wire and the mating surface results in wear of the seal wire and/or movement of the seal wire within its groove. Since the seal wires are typically fashioned from one or more segments, with abutting ends located at one or more locations around their circumference. movement of the seal wire within the groove may result in fretting and/or other wear of the groove resulting from the motion of the seal wire ends. Over time this fretting or wear of the groove enlarges the groove and reduces the effectiveness of the seal wire arrangement,
During repair and overhaul operations it is desirable to restore the seal wire and groove assembly to original or other suitable dimensions and tolerances. However, due to limitations of current repair methods it is frequently necessary to scrap and replace the rotor assembly with a new one having the proper groove dimensions. There remains a need for a repair method which will restore the groove geometry in a durable and economical fashion.